Long summer days are perfect for outdoor activities, and sometimes the best fun is a big game of backyard bowling! It’s one of the best ways I know of to have fun outside and recycle all those empty, 2-liter plastic bottles into good, clean fun. Just pour a few inches of soil, sand, cat litter, or pebbles into ten clean, dry bottles, put the lids back on, and—voila!—you’ve got a set of bowling pins. Arrange ‘em on the lawn, then round up the kids, grandkids, and neighbors, and take turns trying to knock down the pins with the ball of your choice.